Drawing apparatus



J. G. SPARKES.

DRAWING APPARATUS. APPLICATION FILED DEC. 11. 1917.

Patented June 17, 1919.

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' J. G. SPARKES.

DRAWING APPARATUS. APPLICATION men 020.11. 1911 Patented June 17, 1919.

3 SHEETS-SHEET 2.

. G. SPARKES DRAWING APPARATUS APPUCATION FILED DEC. 1?. :92].

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' inDrawing V In is a specification.

. are laborious and tedious.

UNITED sr TEs PATENT OFFICE.

JOHN GORDON srA aKEs, or BIRMINGHAM, ALABAMA.

To all whom it may concern: I

Be it known that I, JOHN GORDON SPARKES, a citizen of the UnitedStatesof America, residing at Birmingham, in the county of Jefferson andState of Alabama, have invented certain new and useful Improvements v ylnventionrelates to a drafting apparatus especially designed for use inmaking- Patent Oilice drawings, technical illustrations, or for use inany branch of drawing whereincopy or reproduction work to the same size,or other sizes, than the original, or where drawing from the objectitself is desired. I

My invention is likewise adapted to any shadow projection sketching,such as the outline from an opaque object or the tracing of a'drawing,or parts of a drawing, onto' another drawing by shadow projection.

In particular, in the making of a Patent Ofiice drawing, it often occursthat an invention is to operate in combination with somestandard pieceof apparatus or machine, as an attachment, and it is then necessary toselect a. drawing or photograph of the machine, generally from acatalogue, and copy it by a laborious process of measure: ment; andiftheillustration is not of a con? venient size to be adapted to the patentsheet the process necessitates the use of a scale or proportionaldividers, both-of which Furthermore these methods are often injurious tothe copy either soiling, or piercing with divider points; whereas whenusing this apparatus the copy is not handled.

Likewise in technical illustrations, parts of an old drawing must beworked into the new, a. reduction of a large working drawing must bemade, or a correct drawing must-be transposed to other material. Oftenthe erfect model of a machine or Object is at liand and to make adrawing of comparatively accurate proportion requires careful.measurements of more or less complication;

and to make an assembled perspective view becomes a matter of free handsketching object require reduction or enlargement the problem becomesmore complicated.

pparatus, of which the follow- DRAWING APPARATUS.

v specification of Letters Patent. Patented June 17, 1919.- 7Application filed December 17, 1917. Serial No. 207,597.

ties, especially if the tracing is to be made from an old blue print ora new drawing built up from several old ones. This apparatus as will beunderstood later provides a means to pass light rays, parallel to eachother by the original Object and to the trac: ing material, therebygiving a sharp definite projection and further provides opportunity forthe tracing of the outline of an object by inserting it in the pathparaxial rays.

It is the object or" this invention to provide a means to convenientlyand economically'accomplish this work primarily 'but it may likewise beadapted to many other drawing Operations as enlarging and reducingornamental letters, designs, trade-marks, maps, etc.

In its preferred design, the instrument is built into a novel cabinetform, so as to provide a convenient drawing desk, embodying the imageforming and projection apparatus as an integral part of the instrument.However the desi used forillustration is only one specific orm and it isunderstood that many other arrangements otdetailscan be made withoutdeparting from the scope of the invention.

In the drawings Figure 1 is a side elevation of the apparatus when openand ready for pro ection work.

Fig. 2 is a front elevation of the apparatus when closed.

Fig. 3 is a sectional view taken on the line 33 of Fig. 1.

Fig. 4 is a plan view of the object plane looking from the line 44 ofFig. 1.

' Fig. 5 is a sectional view taken on the line 5-5 of Fig. 1, and showsthe lens, holder and guide in elevation and section, respectively.

Fig. 6 is aplan view showing the graduations forming the scale along theslot in the lens guide, and is taken from the line 66 in Fig. 1. 4

Fig. 7 is a plan view showing the graduated positions on the object laneguides, and is taken from the line 7'? of Fig. 1.

opaque of the F ig. 8 is a plan View showing the arrangements of theadjusting slots in the top boar'ds.

Similar reference numerals refer to similar parts throughoutthedrawings.

The instrument has two vertical side walls 1, held in rigid and fixedrelative position by a number of spacers 2, disposed horizontally, andare raised from the floor by two bottom pieces 3, which aresubstantially longer than the width of the sides to provide a steady bassupport. The spacers 2 also act as guides for a convenient number ofdrawers 43.1161 5, which slide between the walls 1. The drawers 4 aresubstantially the .width of the cabinet but the drawers 5 are smallerand are spaced from each other by a partition 6, set vertically againstand between the upper spacer 2 and the next lower spacer 2 These spacers2 and 2 are narrower than the lower spacers 2, and this will. beobviously necessary for clearance of the projection apparatus, referenceto which will follow. The lower spacer 2 is extended to lap and extendbeyond a back spacer 7, which is set vertically at the rear ends ofspacers 2 to form a drawer stop and more particularly to prevent amovement of the sides 1 in a plane perpendicular to the spacers 2..Likewise for the same purpose the panel 8 is used under the spacer 2,and it also forms a closure for the lower front of the cabinet.

' It will be noticed, Fig. 1, that the spacers 2, 7 and 8 form, whenscrewed together, a Z-shaped support, the spacer 2 absolutely preventinga movement of the sides in a horizontal plane andthe spacers 7 and 8pre- The upper part of the cabinet is left open to form a mounting forthe projection apparatus and upon inturned flanges 11? of suitablebrackets 11, is mounted a supporting board 12, and by means of twopivoting bolts 13, passing through hearings in the brackets 11, thisboard maybe tilted to any desired angle ranging from horizontal tovertical. a

As the board 12 extends over both of the sides 1, it is necessary forthe corners of the sides 1 to be curved concentric to the hearing bolt13. To retain positively the board in any -desired angle, the bracketsare provided with quadrant arms 14 having slots- 15 concentricallylocated to the bearing bolts 13 and passing a flattened portion v16 onclamp screws 17, passing through the walls 1 of the cabinet. The clampscrew 17 has a head 18 and a hand nut 19, which, when coacting, draw thebracket quadrant arm 14 tight against the cabinet wall 1, therebylocking or clamping the top 12 in any desired position within the rangeof the arm. The flattened shoulder '16 on the clamp screw 17 preventsrotation of the .Screw, when the hand nut 19 is turned;

. The bearing bolts 13 are provided with suitable washers and nuts topermit a free rotation of the board 12, when the clamp screws 17 arereleased. Fastened to flanges 11", inturned from the brackets 11 alongtheir rear vertical edges, is the central part of the cabinet back. Thisback has an '22 and 23, leaving clearance for the free passage in andout of the swinging back 20 and 21. .These back panels 22 and 23 areheld in position by' screws passing through the Walls 1 and braced bybeing screwed to the extension of the spacer 2. sion of the spacer 2 isnotched, or cutaway to pass or receive the guide rods later referred toas 26, when they are brought into closed position.

The back 20 and 21 has out along its longitudinal axis a slot 22, whichguides a bolt 23, which maybe clamped at any position by a hand nut 24.Adapted to slide on the inner face. of this guide is a lens holder 25formed preferably of a front upright portion 25 substantiallyperpendicular to the guide face, and a projecting arm 25, parallelto-the guide face. The arm '25 is provided with a suitable hole to passthe clamp bolt 23, and the back is cut to form a suitable shoulder 25 tocoact'with the head of the bolt so as to prevent turning of the boltwith the hand nut. The arm 25 has cut inits guide following face twoparallel holes or grooves, adapted to receive two rods 26. The ends ofthe rods are firmly retained in the grooves by a metal strap 27 whichpasses over both rods and extends'up ach side-ofthe block 25 and is heldin tight and fixed position by screws 28. The portion 25' has a holebored-through it of size suflicient to retain a lens 29. The lens is.

The extenheld between an annular bead 30 and a ring 31 which is pressedin after the lens is in place. I It isnow obvious that the block 25carrying the lens, can bymeans of the bolt 23 and the hand nut 24 bemoved the entire length of the guide slot 22 and be clamped at anyposition in the slot. The

rods 26 extend downwardly from the block from the object any desiredposition and jaws 47 and at the lower extremity of the guide back 21pass through holes ina lateral cladrlnp 32, which forms a guide for therods an ment of the rods both as to the 21 and to each other. serves tobind the two guide 21, formed by the the back 21. In orderthat anadjustable friction may be provided between the clamp 32 and the rods26, the clamp is divided so as to have a clamping portion 32*, which mayclose by means of a clamp screw 33, against the rods 26 and forcethemagainst the .upper portion-32 n the lower ends of the rods 26,projecting beyond the strip 32 is mounted an object plane, adapted to bemoved to and clamped at any desired position. This plane' consists of aplatform 34, having grooves 35 along its upper edge to engage and whenco-acting with aclamp bar 36 will grasp and clamp on the rods 26. Theclamp bar is held in position by a screw 37, made fast in the platformat one end, and after passing through the clamp bar 36 is provided witha hand nut 38 and washer 39.

It will be noticed that by releasing the hand nut 38 sufficiently thebar 36 can be guide back This clamp 32 also ends of the back the objectplane completely removed. As the object will generally be in the form ofa drawing or photograph a transparent cover 40 is hinged to the plane byhinges This cover will retain the object 44 in assure a fiat smoothsurface. -Lines 42 and 43, scribed on the surface of the transparentcover aid in securing a central alinemento'f the object 44 withthe'optical system.

To illuminate the object an electric lamp. d

45 mounted with a reflecting cover 45 is supported on a bracket theembodiment shown dotted in position in the'longitudinal axis of the'lamp and terminates in a clamp 47,v which has one of its integral withthe bracket and the other 47 separate but retained by a screw 48.sections'of the rods ing the screw 48 sufficiently the jaw 47 can beturned about the screw and the lamp removed from the rod 26.

.In most cases it will be desirable to use two lamps, one on each sideand each clamping its respective rod 26. It will be apparent that thisconstruction is of peculiar advantage as thelampand bracket can beturned about the rod 26 as a center, out plane, sovas to leave thisplane accessible for the insertion and removal of the object. The screw48 provides assures an absolutely parallel move.-,

slot 22 dividing,

l which fold in alinement of j with the image of the object -it may beclamped toward the center and turned to parallelism with the rods. 26and 58 passes through these 46 and clamped to the rod-26 or to theobject plane 34. In

The jaws are shaped to conform to the or tubes 26. By loosenthe requiredpressure to furnish the necessary friction between the jaws and the rodto hold the lamp in any desired position. The lamp is provided with anystandard electrical connections, preferably consistingof a flexible/cord49 terminating in a plug 50. The lower part of the cabinet houses theobject plane and the lamps, when the apparatus is closed. The top board12 has an opening 51 cut through it to pass the light' fr the lens to animage screen support 53 set in\a superimposed board 52. This board 52"has an opening 52 and a recessed inner edge 52 to act as a retainer forthe image screen support 53. Inorder to permit an easy the particularspace on the image screen or paper when it may be desired to project theimage for the purpose of drawing, the board 52 is free to move in anydirection sliding over the board 12, and after alinement and squaring upwith the .paper, by means of the hand nut 58. To make this adjustmentthe board 12 is provided with a through slot 54 parallel to and set infrom-its front edge,

I while the board 52 has a T slot 55 parallel A bolt 56 having a head 57and hand nut slots, the head 57 working freely in the T slot 55 and thehand nut 58 on the under face of the board .12. The head 57 co-actingwith the hand nut 58 through the bolt 56, engages and draws the boards12 and 52 firmly together and locks them in any desired relativeposition within the range of the slots. By means of these crossed slotsand bolt it is apparent that the board 52 carrying the rawing paper canquickly be moved to any desired position. and thereby makes alinement ofthe drawing paper and image simple and without the shifting of theobject or the shifting of the paper by removal from the board. Also theobject may always havetheadvantage of being in the optical axis of thelens system, thereby forming a 'clearer image.

The image screen support 53 is a transparent plane built up of an underrigid plate 53, preferably glass, and having cemented to its upper facea sheet 53 of softer material, preferably transparent celluloid. Both ofthese form the image screen support and are set in the board flush so asto form a perfectly smooth surface at the imageplane.

Now it will be necessary to point out that -in order to form an image itis necessary to inforcement "clamped and the rant 14 and lock the proectlng apparatus a catalogue,

paper should not be used either the glass or celluloid could have aground surface.

To protect this image plane when not in .il iary drawing board when Iprovide an use and for use as a no projection is to be made, auxiliaryboard 59=mounted on by hinges 60 This board 59 also has a function inits raised position as shown in Fig. 1; but this can better be describedin the operation. 7 Onthe top board 12and surrounding the opening 51 1sa downwardly projecting re- 61 which strengthens the top board 12 andalso provides a fastening flange for the large end of a folding bellows62. The forward end or the small end of'the bellows is attached tothesliding lens block 25 by'a smaller fastening flange 61. This bellowsprevents any side light from entering between the lens and the imagescreen.

In operation, the app'a atus in closed position, as shown in Fig. 2, thehand nuts 19 are released and the boards 12 and 52 are swung upwardthrough an angle of about, 25, moving about the center bearing bolts 13and causing the back 20 and 21 to swing outwardly. The hand nuts arethen bolts 17 engage the quad- The lamps 45 are then to clear the objectplane. The object in this case, assume a cut from is inserted on theobject plane 34 and held in position by the transparent cover 40 andadjusted to center by aid of lines 42 and 43. The reduction orenlargement of the object is determined upon, prefin this position.

' erably in tenths and by reference to a calculated table or chart theexact distance required from the center of the lens to the surface ofthe object and the corresponding distance from the center of the lens tothe upper surface of the translucent image screen can be found and thelens and object plane-set and clamped in these positions. The mostconvenient manner however is shown in Figs. 6 and 7 and here thedistances are marked ofi. and denoted in tenths magnification. Suppose,for sake of illustration, that the image is to be shown of magnificationone and four-tenths actual size of object or as shown on the scale 65,Fig. 6, and 66, Fig. 7, fourteen-tenths.- The hand nut 24-. is releasedand the lens block 25 is moved until its indicator67 is at thegraduation fourteen-tenths and clamped. This operation sets the lens atthe proper distance. from the image screen. The clamp nut 38' is nowreleased and the object is moved by sliding the object plane until theindicator 68 is at the position of the graduation 14 on the rod 26, andclamped. It

will be noted that the distances from the ends of the the top board'screen alined with the central and move with it.

The distances having been set, the auxtransparent image screen support.The drawing paper is fastened over this and. the I point oflocation ofthe proposed drawing on the paper. The light is then turned on,preferably by a switch convenient to the operator and board 59 is turnedup to expose the to the lighting circuit. The light emitted I fracted toform the lmage at the image :screen.

Now the auxiliary board 59 serves as a screen to exclude light to apractical extent from the image screen and by its shadow permits a moreapparent contrast of line and field on the image screen. Topass paraxialrays sary to set the lamp at the .focal point of the'lens. The operatorcan now proceed to make the drawing, using'any required instruments. Theimage furnishes the outline and the operator has been relieved of anymeasuring or scaling and may upon the paper, often times 1n ink.

The image screen support plane is built up as previously described witha soft material over the rigid, so that in mechanical work the points ofcompasses may find a firm setting and without danger of turning orblunting the sharp point. v

It will likewise be noted that the image is erect and not perverted. Tocorrect the draw direct 7 5 through the plug 50 and suitable connectlonsto the drafting surface it is only necesordinary inversion it isnecessary to insert the object inverted but perversion 1s corthrough thepaper fore the drawing is made.

Having thus described my invention, what I claim as new and desire tosecure by Let ters Patent, is a i 1. A drawing apparatus comprising anoptical system, a drafting'surface disposed on one side thereof, anobject plane on the other side; centering lines intersecting at theoptical axis of the said system, and disposed between said opticalsystem and said object plane and adapted to be projected with the objectonto said drafting surface.

2. A drawing apparatus comp-risingan optical system, face disposedon-one plane on the other side; centering lines intersectin-g at theoptical axis of the said syssaid optical sysand adapted to term, anddisposed between tem and said object plane, be projected with the objecting surface.

3. A drawing apparatus comprisingan optical system, an adjustabletranslucent an adjustable drafting surside thereof, an object ale 1 ontosaid drafta recess to receive said screen on one side thereof, an objectplane on the other side; centering lines intelsectsurface.

4. A drawin apparatus comprising a support plane %or an optical system,said systembeing adjustable along the longitudinal axis of the saidplane; an adjustable translucent drafting screen set substantiallyperpendicular at one end thereof, an object plane adjustable along theoptical axis, a transparent sheet having centering lines scribed thereoninterposed between said op tical system and said object .plane andadapted to be projected with the object upon said translucent draftinscreen.

5. A drawing esk having side walls spaced from each other and braced bya plurality of spacers set substantially horizontally and vertically,ers interposed between said spacers and walls, a translucent draftingsurface pivot ally mounted on said walls, and a projection apparatuscarried face, said drawers being arranged to 'form projection apparatus,and means to hold said drafting surface in adjusted position. v

6. In a drawing apparatus,'a cabinet, a

hinged support means thereon carrying a;

translucent screen and a projection apparatus adapted to project animage on said screen, and a rearwardly opening recess in said cabinetinto which said pro ection. ap-

paratus swings andis housed when said screen is in normal position.

7. A drawlng apparatus comprising a guide plane, a translucentscreen'set at right,

angles to said plane and at one end thereof,

\a mounting carrying an optical system adjustable along the longitudinalaxis of said plane, guide rods fixed at one end to the said mounting andmovable therewith, guide means on said guide plane to engage and guidesaid rods, an object plane adjustable on "said rods, and means toilluminate said object plane.

8. A drawing apparatus comprising a guide plane, an adjustabletranslucent screen set at right angles to said plane and at one endthereof, a mounting carrying an optical system adjustable along thelongitudinal axis of said plane, guide rods fixed at one end to the sa1dmounting and movable therewith, guide means on said guide plane toengage and guide said rods, an object plane adjustable ,on saidrods,.and means to illuminate said object plane.

9. A drawing apparatus comprising a guide plane, an adjustabletranslucent screen set at right angles to said plane and at one endthereof, a mounting carrying an at one end to the said I plane to engageable therewith,

a plurality of draw-.

by said drafting sur-- gulde means on said gulde optical systemadjustable along the longitudinal axis of said plane, guide rods fixedmounting and movguide means on said guide and guide said rods, an objectplane adjustable on said rods, means to illuminate said object plane,and graduations on said guide plane and said guide rods adapted toco-act with indicators on able therewith,

said mounting and said object plane to indicate predeterminedmagnification.

10. A drawing apparatus comprising a guide plane, screen set at rightangles to said plane and at one end thereof, a mounting carrying anoptical system adjustable along the longitudinal axis of said plane,guide rods fixed at one end to the sa1d mounting and movguide means onsaid'guide' plane to engage andguide said rods, an object plane adustable on said rods, illu rni nating means for said-object planeadjusts.-

ably mounted on said rods, and graduations on said guide plane and saidguide rods adapted to co-act with indicators on said mounting and saidob'ect plane to indicate predetermined magni cation.

11. In combination with .a projection apparatus, a supporting plane setsubstantially at right angles to the optical axis of .said projectlonapparatus, a plane super' imposed on said supporting plane having atransparent plane set in an opening'therein, and an adjusting andclamping means to permit the adjustment of said transparent plane andthe clamping of said planes in position. a

12. A drawing desk having side walls spaced from each other and bracedby a plurality of spacers set substantially horizontally'and vertically,a plurality of drawers interposed between said spacers and walls, anadjustable translucent draftin surface pivotally mounted on said walls,an a projection apparatus comprising a guide plane set substantially atright angles to said translucent drafting surface, a lens systemadjustable along said guide plane, a folding bellows interposed betweensaid translucent drafting surface and said lens system, guide rods fixedat one end to the an adjustable translucent said lens system and movabletherewith,

plane to engage and guide said rods, an object plane ad .justable alongsaid rods, and means to illu- 13. A drawing desk having side wallsspaced from each other and braced by a plurality of spacers setsubstantially horizontally and vertically, a plurality of drawersinterposed between said spacers and walls, an adjustable translucentdrafting surface I Y pivotally mounted on said walls, and a projectionapparatus comprising a guide plane set substantiall at rightangles tosaid translucent dra adjustable along said guide plane, a foldingbellows interposed between said translucent drafting surface and saidlenssystem,guide rods fixed at one end to the said lens system 7 andmovable therewith,

guide means on said guide plane to engage and guide said rods,

an object plane adJustabl along said-rods and means to illuminate saidobjectplane,

ft-ing surface, a lens system I graduations on said vguide plane andsaid."

